• Proceedings of the Korea Electromagnetic Engineering Society Conference
• /
• 2000.11a
• /
• pp.197-201
• /
• 2000

In this paper, a MMIC(Monolithic Microwave Integrated Circuit) broadband drive amplifier for wireless communication system has designed using active feedback method. The MMIC brodband amplifier was designed using 0.5$\mu\textrm{m}$ MESFET of ETRI library. Simulation results show that gain is 22 dB, and gain flatness ${\pm}$1 dB. Maximum output power 15 dBm and noise figure 2.5 dB in bandwidth 500 MHz ～3.0 GHz. The MMIC Broadband amplifer's chip area is 14mm${\times}$1.4mm.

• Electronics and Telecommunications Trends
• /
• v.8 no.4
• /
• pp.1-12
• /
• 1993

ATM 망 기술의 발전으로 BISDN 서비스를 공중망에서 제공하게 되면 LAN 의 충분한 보급으로 BISN 을 통한 LAN 간 연결은 첫번째 응용이 될 것이다. 본 고에서는 ATM 망과 LAN 사이에 연동할 IWU에서 고려해야 하는 문제점을 조사하고 이에 대한 해결 방안을 제시한다. 3 개의 연결형-비연결형 모델을 세워 비교 분석한 후 BISDN(Brodband Integrated Services Digital network)에서 비연결형 서비스 모델을 선정한다.이 모델은 BISDN에서 비연결형 서비스를 제공하는 것으로 Direct 방법과 Indirect 방법, AAL(ATM Adaptation Layer) 3/4와 AAL5 등을 비교 분석함으로써 OSI 에 따른 IWU 모델을 제안한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2007.06a
• /
• pp.565-568
• /
• 2007

In this paper, we designed and fabricated a broadband probe with a double-ridged waveguide for broadband near-field measurements. An exponentially tapered ridge in the rectangular waveguide and a novel waveguide transition were used for broadband impedance matching. The probe has broadband characteristics and its measured impedance bandwidth is approximately 123% (4.17:1) in the range 12.0-50 GHz for standing wave ratios (SWR) < 3.0. The peak radiation gain range and nominal radar cross-section (RCS) are 5.7-14.3 dBi. The performance of this probe was verified using the measured results and is in good agreement with the simulated results.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2007.10a
• /
• pp.223-228
• /
• 2007

In this paper, Wideband antenna using E-shaped stacked patches has been designed and fabricated for 4th generation mobile communication(IMT-Advanced) AccessPoint application. E-shaped patch was miniature and brodband by made the movement route of current long. And inductive of coaxial probe compensates capacitive by slot. Therefore we fabricated to improve the bandwidth of proposed antenna. The E-shaped single patch antenna has an impedance bandwidth of about 13%(510[MHz]), By adding a second patch at the top of the first patch a bandwidth of 56%(2060[MHz]). The final fabricated antenna could have a good return loss(Return loss ${\leq}-10dB$) and a high gain(over 9.6dBi) at the range of 3.23 ${\sim}$ 5.29 [GHz].